The present invention relates to a process for the recovery of 2-pyrrolidone from the reaction product obtained in the preparation of 2-pyrrolidone.
A suitable method for preparing 2-pyrrolidone is the hydrogenation of succinonitrile and reaction with water of the hydrogenation product thus formed, resulting in an aqueous reaction product containing 2-pyrrolidone and impurities. Two processes of this type are disclosed in U.S. Pat. No. 3,644,402, and in U.S. Pat. application Ser. No. 829,781, filed Sept. 1, 1977. These methods yield an aqueous reaction product from which 2-pyrrolidone of quite high purity can be recovered by fractional distillation. However, it has been found that a considerable amount of 2-pyrrolidone, for example up to about 7% of the total present in the reaction product, is lost during the course of this distillation and cannot be recovered.
It is therefore an objective of this invention to provide a method for the recovery of substantially pure 2-pyrrolidone from an aqueous reaction product containing 2-pyrrolidone and impurities whereby the loss of 2-pyrrolidone can be substantially reduced relative to the known distillation recovery method.